Diodes, for example, power diodes, may include heavily p-doped layer, a weakly n-doped layer and a heavily n-doped layer. Such diodes are used primarily in power electronics, for example in high-voltage DC transmission systems. They can have high reverse voltages of a few kilovolts, e.g., more than 4000 V. It is known that such diodes generally experience a transient voltage overshoot in the anode/cathode voltage when turned on with high current gradients.
The maximum transient voltage overshoot that occurs when the diode is turned on is usually set by a suitable choice of diode thickness or a suitable choice of doping for the weakly n-doped zone. In this case, a reduction in the diode thickness or an increase in the doping concentration of the weakly n-doped zone results in lower overvoltages.
This measure, however, is accompanied by a reduction in the diode's reverse voltage. Furthermore, an increase in the doping concentration of the weakly n-doped zone affects the diode's stability toward cosmic radiation.